Numerous industrial units such as heat exchangers requiring a large number of tubes as s component are known to the art. Typically, these units are subjected to a combination of corrosive and stress conditions during operation which damages individual tubes thereby rendering the unit either inefficient or inoperative.
One method of repairing isolated tubes which become damaged in a multi-tube unit is to completely remove and replace the damaged tube. An obvious disadvantage of this method is that not every damaged tube is irrepairable. For example, tubes having minor leaks may be sealed and those tubes which become clogged with fouling buildup may be purged by anyone of a variety of either chemical or mechanical treatments. Another obvious disadvantage of replacing each individual tube which becomes damaged is that the entire unit including mostly operative tubes must be removed from on-line status for extended periods of time. This method is not only expensive but it is also highly inefficient in practice.
One current method for quickly sealing damaged tubes without effecting tube replacement is to seal the open ends of the tube with a tapered plug. The tapered plus is driven into the open ends of the tube and secured therein by welding the plug in place. This method provides a quick efficient solution to isolated tube damage. However, because the tapered plug is driven and welded onto the open tube ends, the tube for all practical purposes becomes irrepairable and during shut-down, the plugged tubes must be replaced with new tubes. Thus, repair of minor damaged or fouled tubes is not practical by means of this method which also invites unnecessary expense in replacement of tubes which can otherwise be repaired.
It has now been found that by practice of the present invention, individual tubes which become damaged in a multitube unit may be simply and efficiently sealed by means of a readily removable cylindrically configurated member which is disposed securely within open ends of the damaged tubular member.